x86/alternatives: Add missing '\n' at end of ALTERNATIVE inline asm

commit b9e705ef7cfaf22db0daab91ad3cd33b0fa32eb9 upstream.

Where an ALTERNATIVE is used in the middle of an inline asm block, this
would otherwise lead to the following instruction being appended directly
to the trailing ".popsection", and a failed compile.

Fixes: 9cebed423c84 ("x86, alternative: Use .pushsection/.popsection")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: ak@linux.intel.com
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Link: https://lkml.kernel.org/r/20180104143710.8961-8-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index dbfd085..cf5961c 100644 (file)
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -140,7 +140,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
        ".popsection\n"                                                 \
        ".pushsection .altinstr_replacement, \"ax\"\n"                  \
        ALTINSTR_REPLACEMENT(newinstr, feature, 1)                      \
-       ".popsection"
+       ".popsection\n"
 
 #define ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2)\
        OLDINSTR_2(oldinstr, 1, 2)                                      \
@@ -151,7 +151,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
        ".pushsection .altinstr_replacement, \"ax\"\n"                  \
        ALTINSTR_REPLACEMENT(newinstr1, feature1, 1)                    \
        ALTINSTR_REPLACEMENT(newinstr2, feature2, 2)                    \
-       ".popsection"
+       ".popsection\n"
 
 /*
  * Alternative instructions for different CPU types or capabilities.